Oil-cooled transformer.



0. KULKA.

OIL GOOLED TRANSPORMER.

APPLICATION 11LBnsBPT-21, 1910.

Patented Sept. 5,1911.

A th/aflttozmew l da v4 e i M?" ff/Mm' 'UNITED STATES PATENT OFFICE.

OTTO KULKA, F HAMBURG, GERMANY, ASSIGNOR T0 GARL FRANZ SANDER,` OF

l HAMBURG, GERMANY.

oIIi-cooLn TRANSFORMER.

Specification of Letters Patent.

Patented Sept. 5, 1911.

Application filed September 21, 1910. Serial No. 583,019.

' To all 'whom it may concern:

v of which the following] is a full, clear, and

exact specification.

This invention relates to oil cooled transformers, and more particularly has reference to improvements inI transformer casings whereby the transformer case can always be maintained full of oil and the oil in the casing will be kept free of water.

It is desirable to maintain the level of the oil in the casing at all times above the core and windings of the transformer, and also to keep the oil free of moisture. As the oil is subject to considerable expansion and contraction by reason of changes in temperature, and is open to the air to give vent to the gases etc., it may absorb considerable moisture.

. According to this invention, I propose to seal the top of a transformer ease with an oil tight cover and to provide in combination with the transformer casing a siphonlike passage having a reservoir for receiving without loss by overflow the excess of oil, when heated, together with a water chamber in which the water can be trapped and drawn ofil without going into the transformer casing.

The invention will be more fully understood in connection with thedescription of the accompanying drawing, wherein- Figure 1 represents an elevation of a transformer casing provided with the invention, a portion thereof being in section. Fig. 2 is a plan view. i

l represents a transformer casing of usual design having a cover 2 which may be fastened thereon by clamps 3, and suitable means to prevent leakage of oil. At the top of the casing cover 2 is provided an upright pipe 3 having a vent chamber 4 closed by a cap 5, and leading from the -pipe 3 is a downwardly inclined pipe 6 leading to chamber 7, which is preferably below the top of the cover 2, and of course below the level of oil in the casing. From the chamber 7 -leads an upright pipe 8 havin an everow reservoir 9 therein, together with a pipe 10 and a closure ca 11.

12 is a cock for drawing off the oil from the casing in case it may be necessary, and 13 is a cock at the bottom of the settling chamber 7 for drawing 0H water or solids which may get into the oil and settle to the bottom of chamber 7.

In operation, the cap 5 is removed to fill the transformer case, the pipes 3, 6 and 8,

` and chamber 7 with oil, up to the level of the line n n, Fig. l, it being understood that the cap 1l is also removed. Having filled the casing with oil, the cap 5 is replaced and locked gas tight and the cap 1l is left slightly open, so that air and gases can vpass where necessary either by variation in the volume of the oil or by liberation of gases from the oil. It will be seen that any moisture which is drawn or formed in the overflow chamber 9 will settle through the to cock 13, and will not pass upward through pipe 6 into the interior of the casing. When the oil becomes very much heated it may rise to the line m-m in Fig. l,it being seen that the'J reservoir 9 is given considerable volume so as to, take care of a large quantity of oil without causing overflow through the pipe l0. It will be seen that the transformer will always be covered with oil even though there be considerable variation in the volume, and also that the oil which iows into thetransformer will be dry, it being understood that dry 4or moisture free oil is to be put in in the first place.

Various modifications and changes in the specific construction herein described may be made without departing from the invention.

Having thus described my invention, I der clare that what I claim as new and desire to secure by Letters Patent is,-

1. An oil containing transformer casing having an overiow pipe forming a reservoir to contain an excess volume of oil, and asettling chamber communicating with said overflow pipe and'having its bottom below the opening into said casing.

2. The combination in a. transformer casing adapted to contain oil, of an inverted Siphon adapted to permit oil to flow to or from the easing, said siphon having its bend below the normal level of oil in the casing.

3. The combination in a closed transformercasing adapted to be filled with oil, of an inverted siphon tube connected with the interior of the casing and having its below the normal oil level in the casing, an enlarged chamber at said bend having a discharge valve, and an overflow tube ex- 15 tending upwardly from said bend above the normal oil level in said casing.

In testimony whereof IaHiX my signature, l

in presence of two witnesses.

OTTO KULKA.

Witnesses:

ERNEST H. L. MUMMENHOFF, EDWARD HoPF. 

